The following United States patents show various designs that have been developed in the past.
______________________________________ No. DATE INVENTOR ASSIGNEE ______________________________________ 2,691,262 10/12/54 Swertfeger 3,754,603 8/28/73 Bogie 4,041,996 8/16/77 Grover Ram Industries 4,259,834 4/7/81 Lambert, e.a. USA - Sec. of Agric. 4,338,985 7/13/82 Smith e.a. Georgia Pacific Corp. ______________________________________
None of these show or suggest the mowing head design of the present invention. Some are dual purpose, U.S. Pat. No. 4,041,996 supposedly can be used to chew up brush besides eradicating stumps. U.S. Pat. No. 4,259,834 is of interest because of its discussion of prior art devices.